A Time-Shifted TV (TSTV) in the prior art is implemented as follows. The stored TV programs are displayed in columns on a client interface according to a preset program schedule of each channel. When a user chooses a TV program at a certain time interval through the Electronic Program Guide (EPG), the system quickly locates a time point of a corresponding media file to play. The most regular TSTV solution is to add the capability of cache and video playing signaling processing on a Broadcast TV (BTV) server.
Currently, a TSTV service and a BTV service are closely associated, and a video stream occupies a larger network bandwidth. Particularly, in an access line, the average access bandwidth of a typical Asymmetric Digital Subscriber Line (ADSL) access line is 6 M to 8 M, while a video stream encoded by Moving Pictures Experts Group-2 (MPEG-2) generally occupies a bandwidth of more than 4 M. In a network over access nodes (ANs), as a TSTV program is in a unicast form, while an original BTV program is in a multicast form, when the user switches from one channel of the BTV to the time-shifted mode, unicast resources need to be newly allocated. In other words, a unicast bandwidth needs to be newly allocated before the bandwidth occupied by the multicast is released, so that the bandwidth becomes inadequate, which raises new requirements on resource allocation.
The solution in the prior art adopts the original unicast and multicast architecture of Next Generation Network (NGN). During switching from the BTV service to the TSTV service, the BTV service is terminated and the resources thereof are released, and then the resources of the TSTV service are applied for, so that the BTV service and the TSTV service originally associated are processed separately, which greatly lowers the switching speed and deteriorates the user experience. Further, the application for the resources of the TSTV may cause a resource admission failure due to the fact that the resources have already been occupied by other services, which may directly result in that the time-shifted service cannot be provided. During switching from the TSTV service to the BTV service, a similar process of firstly releasing and then applying for the resources also exists, and, likewise, the switching speed is lowered.